This invention relates to electrical switches, and more particularly to an improved pushbutton-type switch particularly suited for use on the dashboard of automotive vehicles and the like. Even more particularly, this invention relates to an illuminated pushbutton switch which, in one position transmits a light of one color, and in the second position transmits a light of a different color.
One of the more obvious difficulties encountered while driving an automobile in the darkness is the proper selection of switches, such as for example those used for controlling the windshield wipers, the heater, the headlights, the air conditioner, and various other electrically-operated accessories. Unless the switches are properly illuminated the operator of the vehicle could be distracted while fumbling or searching for a switch. One obvious solution is to illuminate the entire dashboard or panel, but this tends to result in unnecessary eye fatigue. Consequently, the preferred way is to illuminate the individual switches, thereby minimizing eye strain, but at the same time making switch selection easier.
A problem which has been encountered with illuminated switches, however, has been the difficulty to determine at a glance if a given switch is in its "ON" or "OFF" position. Although U.S. Pat. No. 2,883,652 discloses a transparent pushbutton having a translucent top enclosing a plurality of lamps of different colors, which are selectively energizable to indicate the operation of either a primary or a secondary motor, and the existance of any trouble related with a respective motor, the problem with this type of switch is that it requires a plurality of differently-colored bulbs to represent different conditions of operation of the associated circuits, and as a consequence the switch is extremely expensive to manufacture and difficult to install.
U.S. Pat. No. 2,194,241 discloses a pivotal mercury switch containing gases which glow with two different colors to indicate, respectively, two different conditions of the associated circuit. This type of switch, however, is extremely expensive and impractical for use on automobile dashboards.
U.S. Pat. No. 3,729,607 discloses coaxially disposed pushbuttons which display a single color, when their outer ends are disposed in coplanar registry, but which display two colors when the inner pushbutton is extended. This switch, however, does not utilize an electrically-operated lamp for illuminating the switch in either of its positions. U.S. Pat. No. 2,956,446 discloses an illuminated pushbutton switch, but it does not transmit two different colors of light to represent, respectively, two different positions of the switch. U.S. Pat. No. 3,260,830, discloses a rotatable switch the head of which transmits light of differently colored hues depending upon the position of the switch, but it is not a two-position pushbutton.
It is an object of this invention, therefore, to provide a pushbutton-type switch, which can be illuminated to emit one color of light representing the disposition of the switch in one of its two positions, and which transmits a different color of light when the switch is in a second position.
It is an object of this invention also to provide an improved, illuminated pushbutton switch which comprises a plurality of pairs of contacts for controlling a plurality of separate circuits, and novel switch operating elements that prolong the useful life of the switch as compared to prior such switches.